61312-87-6Relevant articles and documents
Method for preparing 4-isobutyl pyrrolidone by solvent-free method
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Paragraph 0011-0012, (2020/04/02)
The invention discloses a method for preparing 4-isobutyl pyrrolidone by a solvent-free method. The method is characterized in that R-type, S-type or racemic 3-(carbamylmethyl)-5-methylhexanoic acid is used as an initial raw material, 3-aminomethyl-5-methylhexanoic acid is prepared through a Hofmann degradation reaction, and an R-type, S-type or racemic 4-isobutyl pyrrolidone product is prepared through a solvent-free reaction. According to the method, currently prepared sodium hypobromite is used for carrying out the Huffman degradation reaction, so that the defects that sodium hypochlorite is easy to decompose and low in reaction activity can be avoided. The generated 3-aminomethyl-5-methylhexanoic acid is subjected to a melting reaction under the solvent-free condition, pulping and purification are carried out, a small amount of oxidation impurities can be removed, meanwhile, the solid form is improved, finally, suction filtration and drying are carried out, and the 4-isobutyl pyrrolidone product with the purity being 98.5% or above is obtained. In the whole reaction process, less solvent is used, the operation is simple and easy, and the method is clean and environment-friendly.
PROCESS FOR PRODUCING OPTICALLY ACTIVE 4-NITRO-BUTANOIC ACID ESTER AND PREGABALIN
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, (2017/12/27)
PROBLEM TO BE SOLVED: To provide a process for producing optically active pregabalin with low number of reaction steps and low cost, as well as to provide a process for producing optically active 4-nitro-butanoic acid ester for use in said process. SOLUTION: Provided is a process for producing optically active 5-methyl-3-nitromethyl-2-alkoxycarbonyl-hexanoic acid alkyl ester by reacting dialkyl malonate and 4-methyl-1-nitro-1-pentene in the presence of a chiral catalyst containing a pyridine bisoxazoline derivative and calcium oxide; and a process for producing pregabalin using the present production process. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
STEREOSELECTIVE REDUCTIVE AMINATION OF ALPHA-CHIRAL ALDEHYDES USING OMEGA-TRANSAMINASES FOR THE SYNTHESIS OF PRECURSORS OF PREGABALIN AND BRIVARACETAM
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Page/Page column 141, (2016/06/06)
The present invention relates to processes comprising a combined racemization and stereoselective reductive amination step in which an aldehyde compound of formula (I) is contacted with an (R)-selective ω-transaminase or an (S)-selective ω-transaminase to racemize the compound of formula (I) and obtain an amine compound of formula (II). These processes are useful for the preparation of precursors of pharmaceutically active agents such as brivaracetam and pregabalin.